APA (7th ed.) Citation

Schmidt, F., Zemlinsky, A. v., Schreker, F., & Gurlitt, M. (1997). Die deutsche Oper des 20. Jahrhunderts: = The German opera of the 20th century. Delta Music.

Chicago Style (17th ed.) Citation

Schmidt, Franz, Alexander von Zemlinsky, Franz Schreker, and Manfred Gurlitt. Die Deutsche Oper Des 20. Jahrhunderts: = The German Opera of the 20th Century. Frechen: Delta Music, 1997.

MLA (9th ed.) Citation

Schmidt, Franz, et al. Die Deutsche Oper Des 20. Jahrhunderts: = The German Opera of the 20th Century. Delta Music, 1997.